Question: Why do blood clots form in hospital patients or patients who are on bed rest? Is there a chemical change?

Josh Makepeace answered on 24 Jun 2013:

Hey rockpeacepunk. I’m not trained medically, but I’ll give you my best answer as I understand it. The fact that your blood is able to clot (blood cells joining up) is normally a great thing, it’s what stops a cut from keeping on bleeding. However, when blood clots inside your body where it’s not supposed to, it can cause serious health problems, like strokes and heart attacks. Apparently, there are lots of different reasons why you can can get blood clots, anything which causes a change in the way your blood clots can causes them. So some medication might make you more likely to get a clot. Also recent operations can mkae it more likely. But one of the most common causes we hear about is being inactive. So I guess that’s the risk with people on bed rest, or on long plane journeys. As far as I can tell, it’s not that these things cause a chemical change in the body, but just because the blood isn’t moving enough, there’s more chance that some of the cells will stick together and start to form a clot. That’s why it’s important to get the blood pumping around every once in a while.

Thanks for the question 🙂